The present invention belongs to a technical field of a game system in which an image is formed through a texture mapping process in a game field constructed in a virtual three-dimensional space and is displayed as a game picture.
Recently, a three-dimensional game becomes popular in which three-dimensional display processing of a game picture is executed as a processing capability of a game apparatus improves. In such three-dimensional games, an object disposed in the virtual three-dimensional space is subject to the three-dimensionally modeling and is divided into a lot of polygons, and a texture having a pattern corresponding to each polygon is mapped on the polygon to thereby form a display image. Therefore, a player enjoying the game is allowed to watch a real game picture in which he or her can freely move in the three-dimensional space.
In the above described three-dimensional game, it is necessary to increase the number of polygons required to perform the three-dimensionally modeling of each object in order to display a high quality and real picture. However, a load in the image processing may excessively be increased with the number of the polygons increasing. Accordingly, it is inevitable to restrict the number of polygons to be used within a certain range for making the game picture in view of the load in the image processing.
On the other hand, to prevent the increase of the number of polygons, it is possible to represent an image by using a texture representing a two-dimensional pattern without dividing the model into polygons, when representing a three-dimensional configuration such as a bumpy configuration. According to such an image representation method, there is no problem when a viewpoint is fixed at a certain position in the game field. However, since the texture can not be varied in accordance with changes of the viewpoint, it is difficult to obtain solidity or plasticity when the two-dimensional pattern on the texture is observed from the viewpoint capable of moving in the game field. Therefore, there is a problem that the real three-dimensional picture can not be displayed, so that the player may feel that something is wrong.
Therefore, it is an object of the present invention to provide a game system capable of displaying a real and high grade three-dimensional picture for a player without increasing the load of image processing when displaying a game field constructed in a virtual three-dimensional space as a game picture.
To solve the above problem, there is provided a game system in which a game field is configured in a virtual three-dimensional space and a display image of said game field visible from a predetermined viewpoint is formed to thereby be displayed as a game picture, comprising: a texture storing device for storing in advance a texture representing a three-dimensional configuration as a two-dimensional pattern; a mapping surface setting device for setting a mapping surface of the texture in the game field; a texture processing device for processing the texture readout from the texture storing device in accordance with a dispositional relationship between the viewpoint and the mapping surface; and a texture mapping device for mapping the processed texture on the mapping surface.
According to the above game system, the texture rendered thereon a display object having a three-dimensional configuration as a two-dimensional pattern is prepared in advance, and the texture is mapped on the mapping surface after being processed corresponding to a view of the display object from the viewpoint. Therefore, when the viewpoint moves in the game field, the two-dimensional pattern can be stereoscopically observed in accordance with changes of the viewpoint without carrying out the modeling of the three-dimensional configuration. Thus, it is possible to display a high grade game picture having solidity or plasticity without excessively increasing the load of the image processing.
In the above game system, the texture processing device may deform a configuration of the texture readout from the texture storing device in accordance with the dispositional relationship between the viewpoint and the mapping surface.
According to this case, the texture is mapped on the mapping surface after being deformed to accord with the view of the display object from the viewpoint when processing the texture. Therefore, it is possible to display a game picture which represents a pseudo-solidity with using a two-dimensional pattern owing to a deformation effect of the texture when the viewpoint moves in the game field.
The texture processing device may extract a part from the texture readout from the texture storing device in accordance with the dispositional relationship between the viewpoint and the mapping surface.
According to this case, the texture partially extracted is mapped on the mapping surface to accord with the view of the display object from the viewpoint when processing the texture. Therefore, it is possible to eliminate a portion not to be observed from the texture in accordance with the viewpoint when it moves in the game field. Thus, a three-dimensional configuration can be reflected in the game picture with using a two-dimensional pattern.
The texture processing device may deform a configuration of the texture readout from the texture storing device, and then may extract a part from the deformed texture in accordance with the dispositional relationship between the viewpoint and the mapping surface.
According to this case, a partial texture extracted from an original texture is mapped on the mapping surface after deforming the original texture to accord with the view of the display object from the viewpoint when processing the texture. Therefore, it is possible to delicately render a complex three-dimensional configuration with using a two-dimensional pattern.
The texture processing device may define an extraction position for extracting said part from the texture depending on an oblique angle of the mapping surface observed from the viewpoint, and may extract said part from the texture readout from the texture storing device in accordance with the extraction position.
According to this case, the texture is extracted at the extracting position depending on the oblique angle of the mapping surface viewed from the viewpoint, when processing the texture. Therefore, even though the angle of view to the display object changes according to the movement of the viewpoint, it is possible to change the view of the three-dimensional configuration in accordance with that angle.
The texture processing device may determine an area to be treated as a dead space in the texture depending on the oblique angle, and may define the extraction position so as to eliminate the area to be treated as the dead space from the texture.
According to this case, the extraction of the texture is carried out to eliminate the dead space in the original texture not to be observed from the viewpoint when processing the texture. Therefore, even though the texture can not partially be observed depending on the viewpoint when the viewpoint moves in the game field, this situation can exactly be displayed in the game picture.
The texture storing device may store in advance a texture on which a surface formed with a recess portion is rendered as a two-dimensional pattern, and the texture processing device may define, as the extraction position, a line shifting on the texture in connection with the oblique angle.
According to this case, when processing the texture, the extraction of the texture is carried out to eliminate, from the recess portion formed on the wall surface or the like, a part to be a dead space when the recess portion is viewed from an oblique angle. Therefore, it is possible to exactly display only a part of the recess portion formed on the wall surface or the like in accordance with the viewpoint when it moves in the game field.
In another aspect of the present invention, there is provided a game system in which a game field is configured in a virtual three-dimensional space and a display image of said game field visible from a predetermined viewpoint is formed to thereby be displayed as a game picture, comprising: a texture storing device for storing in advance a plurality of textures, each of which represents a three-dimensional configuration as a two-dimensional pattern; a surface of the texture in the game field; a texture processing device for processing the textures readout from the texture storing device in accordance with a dispositional relationship between the viewpoint and the mapping surface, respectively; a texture joining device for joining the processed textures to each other at a predetermined joint position corresponding to the dispositional relationship between the viewpoint and the mapping surface; and a texture mapping device for mapping the joined texture on the mapping surface.
According to the above game system, when displaying a game picture of a three-dimensional game, a plurality of textures are prepared in advance, and the respective textures are processed as mentioned above. Then, the textures are mapped on the mapping surface after being joined at a predetermined joining position to each other. Therefore, it is possible to represent a complex three-dimensional configuration by aggregating and merging two-dimensional patterns, thereby enabling display of a game picture through which latitude of stereoscopic expression is extended without using a three-dimensional modeling.
In the above game system, a parameter indicating transparency may be set for each area provided on each of the textures, and, according to the dispositional relationship between the viewpoint and the mapping surface, the texture processing device may change the parameter indicating the transparency for each area on each texture readout from the texture storing device.
According to this case, the textures rendered thereon two-dimensional patterns and transparency for each area is set as a parameter are prepared in advance, and each texture is mapped on the mapping surface after changing the parameter indicating the transparency to accord with the view of the display object from the viewpoint. Therefore, it is possible to exactly display an object having the transparency variable in accordance with an observation direction when the viewpoint moves in the game field.
The game system of the present invention may further comprise a mask pattern disposal device for disposing a mask pattern to mask an image area which is not displayed in the game picture in the texture or each of the textures.
According to this case, an area in the texture except an image area as a display object is masked by using the mask pattern when mapping the texture on the mapping surface. Therefore, regardless of the configuration of the texture itself, an appropriate display can be carried out by forming a mask opening along with the image area with respect to the mask pattern, thereby allowing the game system to obtain the above described effects with using simplified image processing.
In a further aspect of the present invention, there is provided a computer readable storage medium storing a game program for allowing a computer included in a game system in which a game field is configured in a virtual three-dimensional space and a display image of said game field visible from a predetermined viewpoint is formed to thereby be displayed as a game picture, to serve as: a texture storing device for storing in advance a texture representing a three-dimensional configuration as a two-dimensional pattern; a mapping surface setting device for setting a mapping surface of the texture in the game field; a texture processing device for processing the texture readout from the texture storing device in accordance with a dispositional relationship between the viewpoint and the mapping surface; and a texture mapping device for mapping the processed texture on the mapping surface.
In the above described computer readable storage medium, the texture processing device may deform a configuration of the texture readout from the texture storing device in accordance with the dispositional relationship between the viewpoint and the mapping surface.
The texture processing device may extract a part from the texture readout from the texture storing device in accordance with the dispositional relationship between the viewpoint and the mapping surface.
The texture processing device may deform a configuration of the texture readout from the texture storing device, and then may extract a part from the deformed texture in accordance with the dispositional relationship between the viewpoint and the mapping surface.
The texture processing device may define an extraction position for extracting said part from the texture depending on an oblique angle of the mapping surface observed from the viewpoint, and may extract said part from the texture readout from the texture storing device in accordance with the extraction position.
The texture processing device may determine an area to be treated as a dead space in the texture depending on the oblique angle, and may define the extraction position so as to eliminate the area to be treated as the dead space from the texture.
The texture storing device may store in advance a texture on which a surface formed with a recess portion is rendered as a two-dimensional pattern, and the texture processing device may define, as the extraction position, a line shifting on the texture in connection with the oblique angle.
In a still further aspect of the present invention, there is provided a computer readable storage medium storing a game program for allowing a computer included in a game system in which a game field is configured in a virtual three-dimensional space and a display image of said game field visible from a predetermined viewpoint is formed to thereby be displayed as a game picture, to serve as: a texture storing device for storing in advance a plurality of textures, each of which represents a three-dimensional configuration as a two-dimensional pattern; a mapping surface setting device for setting a mapping surface of the texture in the game field; a texture processing device for processing the textures readout from the texture storing device in accordance with a dispositional relationship between the viewpoint and the mapping surface, respectively; a texture joining device for joining the processed textures to each other at a predetermined joint position corresponding to the dispositional relationship between the viewpoint and the mapping surface; and a texture mapping device for mapping the joined texture on the mapping surface.
In this computer readable storage medium, a parameter indicating transparency may be set for each area provided on each of the textures, and, according to the dispositional relationship between the viewpoint and the mapping surface, the texture processing device may change the parameter indicating the transparency for each area on each texture readout from the texture storing device.
The game program may further allow the computer to serve as a mask pattern disposal device for disposing a mask pattern to mask an image area which is not displayed in the game picture in the texture.